Sauber is targeting Force India's sixth place in the constructors' championship by the end of the year, but has acknowledged it won't be easy.

Sauber is currently seventh in the standings, but has recently tapped into a rich vein of form with 38 points from the last four races. By contrast Force India, now just 17 points ahead, has scored one point and dropped off the pace over the same four races.

Sauber team principal Monisha Kaltenborn is being cautiously optimistic about her team's chances, with Toro Rosso in eighth 17 points behind.

"In general we are always looking ahead," she said. "If we continue to be as focused without making any mistakes, then there is still a lot to gain. We know however, that it won't be easy to claim sixth place. And, of course, we will check the rear mirror in order to avoid a nasty surprise."

Kaltenborn explained that Sauber's improvement has stemmed from a revision of the exhaust system at the rear of the car.

"The aero balance of the car was not stable, especially during braking and turning in," she said. "Apart from the measurable implications, the side effect was that the drivers had less confidence in the C32. In addition, we didn't have the resources to quickly modify the car. Instead, this process happened step by step.

"The largest update we brought was in Hungary, where we implemented a modified exhaust concept. We already saw a significant improvement back then, but, of course, it took some time until we were able to get the most out of that. In addition, our understanding of the car improved, which translated to a better set-up. Furthermore, we were able to maintain the high level of quality producing the parts back at the factory. The whole team, in the factory and at the track, did an outstanding job."

The Sauber upgrade coincided with the change back to 2012 construction tyres, which Kaltenborn said had also helped with performance.

"It's not easy to pinpoint that as we brought our largest update at the exact same time. However, I believe in general the tyres helped, which was the opposite last year."